Method and apparatus for adaptive application message payload content transformation in a network infrastructure element

ABSTRACT

Application message payload data elements are transformed within a network infrastructure element such as a packet data router or switch. The network element has application message transformation logic for receiving one or more packets representing an input application message logically associated with OSI network model Layer 5 or above; extracting an application message payload from the input application message; identifying one or more first content elements in the application message payload; transforming the first content elements into one or more second content elements of an output application message; and forwarding the output application message to a destination that is identified in the input application message. Transformations performed in the network element can include field reordering, field enrichment, field filtering, and presentation transformation.

PRIORITY CLAIM Cross-Reference to Related Applications

This application claims the benefit as a Continuation of applicationSer. No. 11/398,983, filed Apr. 5, 2006, which claims the benefit under35 U.S.C. §119(e) of provisional application 60/692,715, filed Jun. 21,2005, the entire contents of which are hereby incorporated by referenceas if fully set forth herein. The applicant(s) hereby rescind anydisclaimer of claim scope in the parent application(s) or theprosecution history thereof and advise the USPTO that the claims in thisapplication may be broader than any claim in the parent application(s).This application is generally related to prior application Ser. No.10/991,792, filed Nov. 17, 2004.

FIELD OF THE INVENTION

The present invention generally relates to data processing techniquesperformed within network infrastructure elements such as routers andswitches. The invention relates more specifically to techniques fortransforming network message payloads into different internal formats.

BACKGROUND

The approaches described in this section could be pursued, but are notnecessarily approaches that have been previously conceived or pursued.Therefore, unless otherwise indicated herein, the approaches describedin this section are not prior art to the claims in this application andare not admitted to be prior art by inclusion in this section.

Software applications operating in a network environment produce orconsume application messages. For example, a client software elementhosted at an end station device such as a personal computer orworkstation may form and send a message to a corresponding applicationserver that is hosted in a network. Each message typically comprises oneor more headers and a payload that contains application-specificinformation. Messages may be contained in more than one data frame,packet, segment, or other unit of organization under a networkcommunication protocol. In the description herein, a “message” is a setof data relating to an application and associated with Layer 5, 6 or 7of the OSI network reference model.

Such application-layer messages often need to be changed or transformedso that applications consuming the messages can handle them. Thesemessages can arrive at a network device over different lower-layerprotocols, such as HTTP, HTTPS, JMS, MQ, RV, and certain proprietaryprotocols that use TCP or UDP as a transport. Typically, a receivingapplication must receive a message in a particular format that theapplication understands. As a result, some intermediary processing unitmust transform an inbound message to the required format for theapplication.

Generally, in past approaches such transformations have been performedusing applications or mechanisms that are running on a host associatedwith an application endpoint. For example, an application server mayinclude transformation logic. But as applications and their messageformats evolve, each sending and receiving application is required toaccommodate an increasing number of different application-layer messageformats. The transformation logic at each application server requiresmodification to accommodate new formats. This is time-consuming andrequires significant resources in programming labor. There is a need foran improved approach for performing application-layer transformationthat does not require re-coding or modifying application servers,clients, or other end stations.

Further, in typical past approaches, application message transformationis performed either by an application consuming the message, or by aprocess or mechanisms running on a host on behalf of the applicationconsuming the message. Alternatively, message transformation isperformed by the application producing the message, based on the targetapplication endpoint.

In all these cases, the number of points at which transformation isperformed increases based on the number of application endpointsproducing or consuming the message. For example, if seven instances of adatabase application were hosted in a particular server, then in theconventional approach, all seven instances would have to perform messagepayload transformation. This is a waste of application processingresources. There is a need for a more efficient approach that cansomehow consolidate, at a single processing point, all message payloadtransformation work for a plurality of instances of an application orfor multiple different applications.

One approach for performing message transformation is described in priorapplication Ser. No. 10/991,792, filed Nov. 17, 2004, of Pravin Singhalet al. (“Singhal et al.”), and assigned to the assignee hereof. Theapproach of Singhal et al. provides mechanisms for transport protocolmessage brokering. For example, the approach of Singhal et al. canreceive a message that uses the HTTP protocol and change that messageinto an MQ message. However, the approach of Singhal et al. does notchange, modify or transform data contained within a payload portion ofthe inbound message. Thus, if an inbound HTTP message contains an XMLdocument as a payload, but a receiving application requires a particularkind of FIX or COBOL CopyBook message payload as input, the approach ofSinghal does not provide a solution. In contrast, Singhal et al. wouldbe able to change the inbound HTTP message into an IBM MQ messagecarrying the same XML document as a payload.

Further, if the inbound message has an XML payload containing a “date”data field that is expressed in “MMDDYY” format, but the receivingapplication requires all dates to be expressed in “YYYYMMDD” format, theapproach of Singhal does not provide a solution.

Thus, based on the clear deficiencies of past approaches, there is aneed for an approach that can perform message payload transformationindependent of the application transport protocols that carry suchpayloads.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements and in which:

FIG. 1A is a block diagram that illustrates an overview of a networkarrangement that can be used to implement an embodiment;

FIG. 1B is a block diagram showing application message payloadtransformation logic in a network infrastructure element such as arouter, in one embodiment;

FIG. 2A is a block diagram of software elements that may be used toimplement XSLT-based application message payload transformation, in oneembodiment;

FIG. 2B is a block diagram of software elements that may be used toimplement XSLTC-based application message payload transformation, in oneembodiment;

FIG. 3 is a data flow diagram that shows transformation of anapplication message payload, in one embodiment;

FIG. 4 is a flow diagram that illustrates a high level overview of oneembodiment of a method for application message payload transformation ina network infrastructure element;

FIG. 5 is a block diagram of a class relationship for an implementationin an object-oriented programming environment;

FIG. 6A is a block diagram showing steps involved in one embodiment ofcreating and deploying transformations in a network infrastructureelement;

FIG. 6B is a block diagram showing steps involved in one embodiment ofcreating and deploying transformations in a network infrastructureelement;

FIG. 7 is a block diagram of a software stack that may be used toimplement one embodiment of application message payload transformationin a network infrastructure element; and

FIG. 8 is a block diagram that illustrates a computer system upon whichan embodiment may be implemented.

DETAILED DESCRIPTION

A method and apparatus for application message payload transformation ina network infrastructure element are described. In the followingdescription, for the purposes of explanation, numerous specific detailsare set forth in order to provide a thorough understanding of thepresent invention. It will be apparent, however, to one skilled in theart that the present invention may be practiced without these specificdetails. In other instances, well-known structures and devices are shownin block diagram form in order to avoid unnecessarily obscuring thepresent invention.

Embodiments are described herein according to the following outline:

-   -   1.0 General Overview    -   2.0 Structural and Functional Overview    -   3.0 Application Message Payload Transformation Approaches        -   3.1×SLT-Based Transformation        -   3.2 Message Flow within a Network Element        -   3.3 Transformation Design Example            -   3.3.1 Transformation Bladelet and Parameters            -   3.3.2 Transformation Policy Configuration            -   3.3.3 Transformation Parser Policy Configuration            -   3.3.4 Class Implementation            -   3.3.5 Creating and Deploying Transformations    -   4.0 Implementation Mechanisms—Hardware Overview    -   5.0 Extensions and Alternatives

1.0 General Overview

The needs identified in the foregoing Background, and other needs andobjects that will become apparent for the following description, areachieved in the present invention, which comprises, in one aspect, adata processing apparatus comprising a plurality of network interfacesthat are coupled to a data network for receiving one or more packetstherefrom and sending one or more packets thereto; one or moreprocessors; a switching system coupled to the one or more processors andpacket forwarding logic, wherein the switching system and packetforwarding logic are configured to receive packets on a first networkinterface, determine a second network interface on which to send thepackets, and to send the packets on the second network interface; andapplication message transformation logic comprising one or more storedsequences of instructions which, when executed by the one or moreprocessors, cause the one or more processors to perform: receiving oneor more packets representing an input application message logicallyassociated with OSI network model Layer 5 or above; extracting anapplication message payload from the input application message;identifying one or more first content elements in the applicationmessage payload; transforming the first content elements into one ormore second content elements of an output application message; andforwarding the output application message to a destination that isidentified in the input application message.

In one feature of this aspect, the apparatus further comprises sequencesof instructions which, when executed by the processor, cause theprocessor to perform transforming the first content elements into one ormore second content elements of an output application message by any offield reordering, field enrichment, field filtering, and presentationtransformation.

In another feature, the apparatus further comprises sequences ofinstructions which, when executed by the processor, cause the processorto perform transforming the first content elements into one or moresecond content elements of an output application message by any one of:structural reordering; complex map, schema, and dictionary-basedtransformation; content formatting at the presentation layer, such asXML to HTML and WML transformation, or transformation based on requiredmedia types of the receiver; personalization; security credentialmapping; content aggregation; content splitting; service interfacevirtualization; performing content-based lookup, extraction, routing anddistribution; content validation; data validation; and code pagetranslation.

In a further feature, the application message payload transformationlogic comprises a transformer bladelet that uses a transformationservice, and a transformer factory that creates a transformer functionthat is registered in the transformation service. In another feature,the transformer function is coupled to an extensible XSLT transformerthat comprises an XSLT processor and an XML reader. In yet anotherfeature, the transformer function comprises a translet-basedtransformation function, and wherein the transformer function is coupledto an XSLTC compiler, and wherein the transformer function compriseslogic configured to invoke the XSLTC compiler to compile an XSLtransform file into one or more translets.

In still another feature, the apparatus comprises any of a packet datarouter and a packet data switch in a packet-switched network. In yetanother feature, a transformation policy is received, and specifies whattransformation operations to perform on the application message payload,which translator to use, and a content type of the output message, andthe transforming step is performed based on the transformation policy.

In other aspects, the invention encompasses a machine-implemented methodand a computer-readable medium configured to carry out the foregoingsteps.

2.0 Structural and Functional Overview

FIG. 1A is a block diagram of network elements involved in anapplication message payload transformation approach according to anembodiment. FIG. 1B is a block diagram showing application messagepayload transformation logic in a network infrastructure element such asa router, in one embodiment.

Referring first to FIG. 1A, a sender application 102 is coupled througha network 104 to a receiver application 106. The network 104 comprisesone or more network infrastructure elements 110, such as routers orswitches. Each of the network elements 110 comprises one or more blades,bladelets, scriptlets, or other software elements, alone or incombination with hardware or firmware elements, that implementapplication-layer message inspection and related application messagepayload transformation functions as described herein. An “applicationmessage,” as used herein, refers to a message emitted or consumed by asoftware element that is logically located at Layer 5 or higher of theOSI reference model.

A commercial embodiment of network elements 110A may comprise routers orswitches from Cisco Systems, Inc., San Jose, Calif., with blades havingApplication-Oriented Networking Services (AONS) capabilities. In someembodiments, network elements 110A are termed “AONS nodes” or “AONSendpoints.” Other network elements 110B may be non-AONS nodes. Further,network elements 110A need not use Cisco AONS technology; the networkelements can comprise routers or switches that use other internalelements for performing message inspection, processing or transformationwithin the network elements. Thus, the use of AONS in an embodiment isnot required, and all references herein to AONS elements are providedmerely to illustrate a clear example, and not as limitations.

As seen in FIG. 1B, in some embodiments sender 102 is coupled through alocal network 103 to an internetwork 120 that is coupled to a secondlocal network 112. Either network 103, 112 may have network elements 110that implement the techniques herein. As an example, in FIG. 1B localnetwork 112 hosts router 110, comprising AONS blade 116 and applicationmessage payload transformation logic 108. In certain embodiments all thenetwork elements 110 include application message payload transformationlogic 108, which comprises one or more computer programs, programmaticobjects, or other software elements that implement the functionsdescribed herein.

AONS endpoints may use different formats for the messages that theyproduce or consume. For example, a message produced by an endpoint mayconform to a format that may be different from the format expected by anendpoint that consumes the message. Further an endpoint may produce orconsume XML or non-XML messages or use a different structure for messagecontent. In the example of FIG. 1, the sender of a message may specifycertain customer information in a detailed form, whereas the receiver ofthe message only expects abbreviated customer information.

In other examples, transformation of an application message payload maybe needed for the sender 102 and receiver 106 to communicate and processrequests and responses. Example message payload transformations includefield reordering, field enrichment, field filtering, and presentationtransformation.

In Field Reordering, sender 102 sends a message that contains fields ina certain order that is different from an order that receiver 106requires. For example, sender 102 sends a message with the fields ofTable 1A below, but receiver 106 requires fields in the order of Table1B:

TABLE 1A SENDER FIELD ORDER <shipping-address><first-name>John</first-name> <last-name>Doe</last-name> <...></shipping-address>

TABLE 1B RECEIVER FIELD ORDER <shipping-address><last-name>Doe</last-name> <first-name>John</first-name> <...></shipping-address>

In Field Enrichment and Field Filtering, sender 102 sends someinformation that receiver 106 does not expect. Thus, the informationneeds to be filtered so that receiver 106 can correctly process themessage. For example, sender 102 may include a <middle-name> field indata representing a person in a shipping address, but the receiver 106may not expect that field. In response, in the approach herein anapplication message payload transformation process removes theunexpected field before delivering the message to the receiver 106.Alternatively, if receiver 106 does expect a middle name field butsender 102 sends a message that does not have that field, then theapplication message payload transformation logic 108 inserts an emptymiddle-name field.

In Presentation Transformation, a message payload is transformed toconform to a specific presentation format that the receiver 106 expects.For example, assume that receiver 106 sends a response carrying an XMLpayload, but sender 102 needs to display the response on a browserassociated with the sender. The application message payloadtransformation logic 108 transforms the XML data into an HTML documentand places the HTML document into the message payload before forwardingthe message to the sender 102. As a result, sender 102 can display thecontent of the payload. Alternatively, if the receiver 106 is using adevice that requires content in a message payload to be displayed be inWML, then the application message payload transformation logic 108converts the message payload to WML so that the receiver can correctlydisplay the content.

As another example, the application message payload transformation logic108 can transform a non-XML message payload to a corresponding XMLformat. For example, assume that a message payload that is in CSV formatneeds to be presented to receiver 106 in an XML format. Alternatively,assume that sender 102 sends a FIX message, but receiver 106 expects themessage to be in FIXML format. In both cases, the application messagepayload transformation logic 108 transforms the payload from FIX formatto FIXML format and forwards the message to the receiver 106.

Generally, in all the preceding cases, the application message payloadtransformation logic 108 performs a transformation function on anin-coming message and produces an out-going message. In an embodiment,local network 112 is associated with one or more receiving applicationservers 106A, which host one or more instances of one or moreapplications. Thus, in the arrangement of FIG. 1B, router 110 isproximate to the receiving application servers 106A, and can performapplication message payload transformation for all the applicationservers. For example, sender 102, and other senders at differentlocations in networks 103, 120, might send different requests todifferent instances of applications on different application servers106A. The application message payload transformation logic 108 canperform application message payload transformation for all suchrequests, relieving the application instances and application servers106A from the processing burden of performing application messagepayload transformation for each request.

Alternatively, if router 110 is located in local network 103, the routercan perform application message payload transformation when sender 102emits messages and before the messages reach the application servers106A. In all such cases, the data processing efficiency of theapplication servers 106A is greatly improved because router 110 isresponsible for message transformation, and the application servers areresponsible only for performing substantive application functions.

Thus, according to one embodiment, message payload transformation isperformed in a network device based on the requirements of a consumingapplication. In this approach, a message is transformed outside theapplication producing or consuming such message. In a specificembodiment, message payload transformation is performed in a networkinfrastructure element, such as a router or a switch in apacket-switched network.

When message payload transformation is performed in a network device,the transformation can be performed on a device that is closer to theapplication that is producing the message or the application that isconsuming the message. As a result, if there are multiple instances ofan application running, possibly on different hosts, then a singledevice through which all the messages are passing can perform the neededtransformation. Accordingly, efficiency of the overall network isimproved.

In an embodiment, message payload transformation is specified bydeclarative policies based on the source and target endpoints of theapplication and contents of the message. A policy can define a “custom”message payload transformation in terms of particular messageattributes, variables or values. A policy defines what part of a messageis operated upon, how to transform the message, and the form of theoutput. The policies can be deployed on a network device at which themessage payload transformation is performed.

In this approach, applications do not need to change based on changes inthe kind of message that the applications consume. Further, when messagepayload transformation is performed on a network device, thetransformation can be performed at fewer locations in the network, thusreducing application processing resources.

In one embodiment, XSLT-based Transformation Engines perform XML andnon-XML message transformation. The XSLT-based Transformation Enginesimplement the XSLT 1.x and XSLT 2.0 specifications as defined by the W3Cconsortium (w3c.org). At the time of this writing, XSLT specificationsare available online in the folder /TR/xslt of the domain “w3c.org” onthe World Wide Web. In one embodiment, the application message payloadtransformation logic 108 is extensible in its use of XSLT processor.Thus, the application message payload transformation logic 108 isstructured to allow the use of a different XSLT processor if required.

In an embodiment, the application message payload transformation logic108 is extensible. The application message payload transformation logic108 can be augmented by integrating a third party application thatprovides a specialized transformation function. For example, a scriptletcan be used to build a transformation component that uses a third-partytool or application. The application message payload transformationlogic 108 performs transformations only on message payloads, and is notinvolved in the transport mechanism that is used to move the messageamong network elements.

Extensions to the application message payload transformation logic 108can be implemented by providing a Parser Plugin and Custom Transformerextension. In an embodiment, the Parser Plugin and Custom Transformerextension are JAVA language object implementations, and are developedusing the JAVA development environment. For example, creating a ParserPlugin Package in JAVA can be performed to extend the applicationmessage payload transformation logic 108.

In one embodiment, Transform and Transform Parser bundles,Transformation Policies, Transformation Flows are created and deployedto network elements 106. After such deployment, network elements 106 canreceive and transform messages. In an embodiment, application messagepayload transformation logic 108 performs one or more message payloadtransformations include any of field reordering, field enrichment, fieldfiltering, and presentation transformation. Such transformations mayinclude structural reordering; complex map, schema, and dictionary-basedtransformation; content formatting at the presentation layer, such asXML to HTML and WML transformation, or transformation based on requiredmedia types of the receiver; personalization; security credentialmapping; and other transformations.

Transformations also may include content aggregation and splitting. Forexample, multiple MIME parts in a message can be aggregated or split. Ina SOAP message, the headers can be split from the body and each piececan be used in different ways. The aggregation, splitting, enrichment,filtering, and mapping techniques described herein can be implemented toprovide interoperability of application messages across differentstandards. Further, content encoding can be performed. Service interfacevirtualization techniques can be achieved by using transformations tocarry out interface splitting and interface versioning.

Further, application message payload transformation logic 108 may beconfigured to parse message content and then perform content-basedlookup, extraction, routing and distribution. For example, atransformation can specify extracting particular content from anapplication message payload, placing the content in a new message, anddistributing the new message to another node, such as a monitoring node.

Additionally or alternatively, application message payloadtransformation logic 108 may be configured to perform content validationand data validation based on data structure and data type, for either asource message or destination message. In this embodiment, applicationmessage payload transformation logic 108 examines payload field valuesand determines, based on a transformation schema, whether the fieldvalues are valid in terms of structure and content. If field values arenot valid, then the transformation schema specifies how to transform thevalues into valid values. Thus, semantic message content transformationfor an application payload can be performed.

Additionally or alternatively, application message payloadtransformation logic 108 may be configured to perform code pagetranslation. In code page translation, normalized content as maintainedby a service (e.g., Unicode character encoded content) is mapped to alocale-specific content encoding. Elements representing times, dates,calendar entries, etc., can be transformed into an encoding or formatthat a receiving application requires. Alternatively, a request messagethat conforms to a locally required content encoding may be transformedinto a normalized content encoding and then sent to a service.

Embodiments allow adaptation and extension of the mechanisms thatperform application message payload transformation. For example, anadministrator or other user can add new or different XSLT Transforms,Parser Plugin Transforms, or Custom Transforms to accomplish particulardesired forms of application message payload transformation. Thus, theuser can build upon existing transform logic that is available, usingtransforms that have been uploaded by the same user or other user.Therefore, a user can dynamically apply transform logic without bringingdown the host device to install new software.

Further, “chain” transformation processing is supported in which anetwork element may apply transform logic successively on an applicationmessage payload. Thus, more than one transform may be appliedsuccessively to a content payload that is retrieved from an incomingmessage before the payload is transformed into result content in anoutgoing message. In an embodiment, an overall transform step comprisesone or more transform steps, implemented in one or more transformbladelets in a workflow that successively transforms the content.

Embodiments are implemented in network elements such as routers andswitches. As a result, embodiments implement the notion of sandboxing,in which message transformation is performed within a network elementbefore messages reach applications. This approach provides isolation ofthe transformation functions and allows a single network element totransform all messages destined to multiple instances of an application.

3.0 Application Message Payload Transformation Approaches

This section describes functions performed to accomplish applicationmessage payload transformation for an incoming message represented in anXML format.

3.1 XSLT-Based Transformation

In one embodiment, XSL Transform (“XSLT”) based transformation isperformed. In this approach, an XSLT specifies how an input message istransformed to produce an output message.

The XSLT is created in advance of message processing, based on knownschema of input messages and output messages. The XSLT can be createdusing any existing XSLT design tool. During runtime, an XSLT processorin the application message payload transformation logic 108 receives theXSLT and an input message. The XSLT processor applies the transform tothe message and produces an output message. The application messagepayload transformation logic 108 then directs other functional elementsof the network element 106 to forward the message to its destination.

The XSLT can produce an output message having an XML payload or anon-XML payload. FIG. 2A is a block diagram showing functional elementsthat may be used in application message payload transformation logic 108to perform application message payload transformation either for an XMLpayload or a non-XML payload. When an inbound message comprises an XMLpayload 204, the XML payload is received at XSLT translator 202. Thetranslator 202 applies a previously created XSLT transform 210 to themessage, resulting in generating an output message 214.

In another embodiment, when a non-XML input message is used, duringdesign time an extension to the AON Message Parser component is made andregistered with AON so that a non-XML input message can be parsed toproduce a corresponding DOM Source 206, or emit SAX events that a SAXreader 208 reads, for an equivalent XML input message. The DOM Source206, or output of the SAX reader 208 after processing by a SAXtransformation handler 212, provides the XSLT translator 202 with inputequivalent to an XML input message. The translator 202 applies apreviously created XSLT transform 210 to the message, resulting ingenerating an output message 214.

Thus, the xmlDoc reader, non-XML Doc Reader, CSV Reader, and FIX Readerreferenced in FIG. 2A represent extensibility mechanisms for theapplication message payload transformation logic 108.

In one embodiment, translator 202 comprises the XALAN processor, whichis supplied with the JAVA Development Kit from Sun Microsystems, Inc.Alternatively, the JD-XSLT processor may be used.

FIG. 2B is a block diagram of an embodiment that uses compiled XSLT(XSLTC) based transformation. The elements of FIG. 2B function in amanner that is similar to the XSLT-based transformation approach of FIG.2A. However, the elements of FIG. 2B provide performance advantages overthe approach of FIG. 2A. For example, in FIG. 2B, XSL transforms arecompiled into to Translets 216. Each Translet 216 is a JAVA class thatis generated as a result of compiling a specified XSLT transform usingXSLTC compiler 218. An XSLTC compiler and associated framework for useas XSLTC translator 202 is available in the Apache open source project,and is specifically available at the time of this writing linked in thefolder /xalan-j/xsltc/ of the domain “xml.apache.org” on the Internet.Alternatively, an XSLTC framework is commercially available under thetrade name Gregor from Ambrosoft.

The binary Translets files 216 are used to transform an incoming messageto an out-going message. Once XSL transforms are compiled, Transletclasses are created and can be packaged in a JAR file and made availableto the XSLTC translator 202. During runtime, the XSLTC translator 202uses the Translets to apply a transformation to an incoming message.

3.2 Message Flow within a Network Element

In one embodiment that is implemented using Cisco AONS, transformationof data present in a message is accomplished by designing a flowcomprising of three tasks: data extraction, transformation andcomposition. Each of the tasks is implemented using an AONS Bladelet. Aninput message is processed through various components before datapresent in the message is transformed and put in the outbound message,as now described.

FIG. 3 is a data flow diagram that describes a transformation data flowin which data from a message is transformed and provided in an outboundmessage. In step 1, message content to be transformed is extracted fromthe input (request or response) message 302 and provided as an input“msg-content” element to MIMEExtractor bladelet 304. The MIMEExtractorBladelet also receives additional content search criteria and extractsMIME contents from the message exports it in a content list flowvariable.

In step 2, a Transformer Bladelet 306 receives a list of content totransform and a transform profile name. Based on the transform profile,the Transform Bladelet 306 transforms contents from the input contentlist by invoking a transform handler (step 3) of the XSLT transformer202. The invocation of step 3 causes the XSLT transformer 202 to invokea runtime element of XSLT processor 310, at step 3 a.

The Transform Bladelet 306 receives an additional parameter (not shown)to decide if the contents in the input content list should be replacedby the transformed contents. If not, the Transform Bladelet 306 placesthe transformed contents in an output content list flow variable, whichis passed to MIMEBuilder 308, which takes the transformed contents fromthe flow variable content list and takes a MIME Content object. TheMIMEBuilder element attaches the transformed content and creates anoutput MIME content object.

A CreateMessage Bladelet 312 takes the MIME content object that has thetransformed content, creates an output message 314, and sends the outputmessage to the indicated destination using the parameters from theinbound message 302. In an embodiment, all steps of FIG. 3 are executedin software elements that are hosted in a network infrastructureelement, such as a router or switch. In an embodiment, applicationmessage payload transformation logic 108 (FIG. 1A, FIG. 1B) implementsthe elements and functions of FIG. 3.

In one embodiment, the transformation algorithms and logic describedherein are implemented in a Transformation Bladelet and TransformationService, which are described further herein. In general, theTransformation Bladelet receives an input content list and applies atransformation to result in creating an outgoing transformed contentlist. The Transformation Bladelet also receives an overwrite option,which specifies whether the contents in the input content list should bereplaced by the corresponding result content. The TransformationBladelet also receives two profile parameters; a first profile parameterspecifies a style sheet to use, and the second profile parameterspecifies a specific parser plug-in to use.

FIG. 4 is a flow diagram of one embodiment of a process of applicationmessage payload transformation. In step 402, Initialization isperformed. In one embodiment, initialization comprises reading theBladelet parameters, including an inputContentList, overwriteOption,stylesheetProfile and parserPluginProfile. Initialization also includesretrieving a Transform Service Implementation object.

As indicated at step 404, for each content element in the input contentlist, the following steps are performed. In step 406, a content elementis selected from the list, and a transform Source object (in Src) iscreated. In one embodiment, step 406 comprises determining whether acontent stream is available (step 408), and if so, creating a streamsource (step 410). Applications sometimes use content streams as a meansfor reducing the memory requirements for storing message payloads.Otherwise, as tested at step 412, if the content element comprises XMLor SOAP content, then a DOM Source is created at step 414.

In step 416, a Stream Result object is created to hold the result of thetransformation. Streaming transform for XML (STX) may be used to createstream results.

In step 418, a TransformService.transform method is invoked. Thefollowing elements are passed to the method: in Src, styleSheetProfile,parserPluginProfile. A “result” variable of the method contains theresult of the transformation.

In step 420, a resultContent object is prepared from the result of thetransformation. In one embodiment, step 420 involves inspecting thecontent to determine if it is XML content, and if so, creating an XMLresult content value from the result data returned in step 418.Otherwise, the result is in stream content.

As indicated at step 422, if more content is present in the inputcontent list, then control transfers to step 404.

At step 424, if the overwrite flag is true, then in step 426 thecontents in the input content list are replaced with the correspondingresult content object.

In step 428, the result of the content object list is placed in the flowvariable TransformedContents. In step 430, the output Path Success isset and control returns to a calling method. When the process of FIG. 4returns, other logic in the network element is responsible to forwardthe output message to the destination identified in the input message.Such a forwarding operation includes selecting an output interface andusing a switching system, such as the switching system of a packet datarouter or a packet data switch, to forward one or more packetscontaining the output message to a destination. Thus, in one embodiment,the approach herein is implemented in a system that provides bothapplication message payload transformation functions and logic forreceiving packets, performing a forwarding or routing decision, andforwarding or routing the packets to destinations.

If an exception occurs, as indicated at step 432, a BladeletException iscreated and the exception is thrown.

3.3 Transformation Design Example

This section describes parameters that may be used, in one embodiment,with the Transformation Bladelet and Transformation Service.

3.3.1 Transformation Bladelet and Parameters

This section describes input, output and exported parameters for theTransformation Bladelet, according to one embodiment. In an embodiment,input parameters include “Input,” “OverwriteContent,” “StylesheetProfile,” “ParserPluginProfile,” and “Update Message.”

The Input Parameter has the type ContentListlterator. This parameterspecifies a list of contents to be transformed. Content can be XML orSOAP content, or stream content that may have some non-XML data.

The OverwriteContent parameter is a Boolean value that specifies if thecontents in the input list should be replaced with the transformedcontents. If true, the input contents are replaced with the transformedresult content. If false, a list is created with the resultingtransformed contents, and the list is exported in theTransformationResult flow variable.

The StylesheetProfile parameter is a Policy parameter that specifies thename of the transformation profile to use. Each transformation profilecomprises information about which XSLT Transform file to use, Vendorname and Transform Package name. Using the attributes defined in aprofile, the transformation service selects a transform from avendor-specific transform package and applies the transform to the inputparameter. A profile also can specify a particular XSLT Processor touse.

The ParserPluginProfile is a Policy parameter that specifies a parserplugin profile. It also specifies a default factory for XSLT basedtransformation. Customer developed parser plugin to parse specificnon-xml content can be provided a in transform parser bundle and can bespecified in this profile.

The UpdateMessage parameter is a Message that specifies if messagecontent should be replaced by transformed content. The UpdateMessageparameter can take a flow variable value that corresponds to request orresponse message.

In an embodiment, one output parameter is provided and comprises aTransformedContents parameter of type ContentListlterator. TheTransformed Contents parameter defines a flow variable that contains thelist of transformed contents.

In an embodiment, one exception is defined, and may be named theTransform-Failures exception. If the transformation operations definedherein are successful, an output path of Success is set. However, if anexception occurs, an exception ID is set, and a recoverable BladeletException is thrown. An exception can occur, for example, due to anincorrect transformation or parser profile, bad input data, use of a badtransform, etc.

3.3.2 Transformation Policy Configuration

In one embodiment, a transformation policy file defines a set ofproperties that specify which XSLT Transform to use from a specificTransform Bundle. Table 2 identifies example attribute names andattribute descriptions that can be used in an implementation.

TABLE 2 TRANSFORMATION POLICY FILE CONTENTS Attribute Name DescriptionStylesheetName Specifies the name of the transform file to use. The filemust be present in the Transform Bundle specified by the parametersbelow. The transform file indicates what specific fields to transformand what output fields should result from the transformation. BundleNameSpecifies the name of the transform bundle. Content-Type This is used toset the content type of the target content when the input content isstream content and its type is not known. UseCompiledTransform If ‘Yes’,then it indicates that the specified transform be compiled.TransformerFactory Specifies XSLT Transformer that will be used in XSLTBased transformation, such asjd-xsltorg.apache.xalan.processor.TransformerFactoryImpl

3.3.3 Transform Parser Policy Configuration

In an embodiment, a transformation parser policy file defines a set ofproperties that specify a Content Parser Plugin to use intransformation. Table 3 identifies example attribute names and attributedescriptions that may be used in an embodiment.

TABLE 3 EXAMPLE TRANSFORM PARSER POLICY FILE Attribute Name DescriptionParserClassName Specifies the name of the content parser plugin class.In one embodiment, this class implements the org.xml.sax.XMLReaderinterface. Alternately the class can extend the abstract classcom.cisco.aons.service.transformTransformXMLReader. The content parserplugin class is used to parse data from input stream content and provideequivalent XML content, which is used as input for XSLT Transformation.BundleName Specifies the name of the Parser Plugin Bundle.AONSTransformerfactory This parameter is optional and specifies afactory that implements an XSLT transformer.

3.3.4 Class Implementation

Table 4 describes interfaces and classes that can be used to implement atransformation service.

TABLE 4 EXAMPLE TRANSFORMATION SERVICE CLASSES Class/InterfaceDescription TransformationService This interface is derived from aService interface in AONS. It provides methods that perform messagetransformation. TransformationServiceImpl This class implements theTransformationService interface. It instantiates and initializesspecific transformers. AONSTransformer This interface defines methodsthat perform transformation. A specific transformer must provide animplementation of this interface. An example of specific transformer isXSLTTransformer. AONSTransformerFactory This interface defines a factoryinterface for a transformer. A specific transformer factory mustimplement this interface. An example of specific transformer factory isXSLTTransformerFcatory. TransformationBladelet This class defines aTransformation Bladelet and uses TransformerServiceImpl to performmessage transformation.

FIG. 5 is a class diagram that describes high-level programmatic classesthat can be used to implement transformation functions in anobject-oriented programming environment. The classes of FIG. 5 can beclassified based on the functionality they provide. For example, a classimplementing the Transformation Bladelet functions described herein isthe TransformationBladelet class. The TransformationBladelet classimplements the initialization and transformation logic, extractsBladelet parameters from the Bladelet context and invokes thetransformation function using the Transformation Service.

The Transformation Service class of FIG. 5 comprises one or more classesthat implement specific Transformer and Transformer Factory classesbased on either the XSLT transformation mechanism described herein or anexternal transformation mechanism. External mechanisms may be used toinvoke transformation functions that are provided by third partyapplications. Examples of such applications include Contivo and TraceFinancial.

The Parser Extension class of FIG. 5 enables extensions to an AONSparser. In one embodiment, AONS supports XML and non-XML messages. XMLMessages are easily understood and parsed by AONS. However, for non-XMLmessages an extension is provided that can understand the non-XMLmessages and provide a corresponding equivalent XML message. Theextension implements an XMLReader interface by extending theAbstractXMLReader class. In this approach, the extension emits SAXmessages for an equivalent XML message format.

FIG. 7 is a block diagram of a software stack that may be used toimplement one embodiment of application message payload transformationin a network infrastructure element. A first lower layer 704 comprises aC-based parsing and XSLT library, and a JAVA-based XML parser such asXerces from the Apollo open source project. Optionally, a third-partyruntime library for a third-party transformer may be included, such asthe Contivo runtime library. A second lower layer 706 comprises an XSLTadapter, and a JAVA-based XSLT processor. Optionally, a third-partytransformation handler module may be included, such as the Contivotransformation handler.

A transformation server 710 runs logically on the preceding elements ofFIG. 7. Transformation server 710 is coupled to a handler registry forregistering transformation handler functions in the transformationserver.

A transformation bladelet 712 runs logically on the transformationservice and performs the functions previously described to generate oneor more transformed messages 714. The transformation bladelet 712 alsocan generate first and second messages 716, 718 or signals indicatingwhether a message was transformed (message 716) or not transformed(message 718).

One or more transformation functions 720 are coupled to transformationbladelet 712 and determine what specific transformation operations areperformed. For example, an XSLT-based transformation function 722 maycomprise a mapping of name-value pairs for input messages and outputmessages. Functions 720 include an enumeration 724 of all installedfunctions and a result transformation 726 that indicates how to map thesource message to a flow variable for output.

3.3.5 Creating and Deploying Transformations

FIG. 6A is a block diagram showing steps involved in one embodiment ofcreating and deploying transformations in a network infrastructureelement; FIG. 6B is a block diagram showing steps involved in oneembodiment of creating and deploying transformations in a networkinfrastructure element.

Referring first to FIG. 6A, in step 1, a transformation is defined andcreated in abstract form. Typically a business analyst associated withan enterprise that owns or operates a network (“customer”) hasresponsibility to define required data transformations, based upon theapplications that the customer uses. In step 2, the transformation isgenerated and stored using a third-party data transformation tool. Theoutput of the tool may comprise one or more XSLT style sheets or customprogram code. At step 3, such output of the tool is stored in a filesystem.

At step 4, an administrator logs in to a configuration and provisioningserver. At step 5, the administrator initiates an upload function. Asshown at step 6, the XSLT style sheets or custom code that was stored atstep 3 is uploaded from the file system to the configuration andprovisioning server, and packaged appropriately for provisioning ordeployment. At step 7, the XSLT style sheets or custom transformationcode is provisioned to a network device 110.

In one embodiment, the network device 110 hosts an AONS Design Studio(ADS) application and an AONS blade.

Referring now to FIG. 6B, in another embodiment, a transformationprogram bundle is created using Cisco's AONS with the following steps.First, a transform bundle and a transform plugin bundle are created. Forexample, a first bundle 608 comprising a manifest, one or more XSLTtransform packages, and one or more JAR files is created using the AONSDesign Studio (ADS) 602, commercially available from Cisco Systems, Inc.The user provides the name of the package, version, vendor name,description, properties of the bundle, etc., and then adds one or moreXSLT files or packages to create a transform bundle. Similarly, a secondbundle 610 is created comprising a parser plugin class and one or moreJAR files. Once each bundle is created, the bundle is saved in a file ina location that is specified by the user.

The transform bundle and the transform parser plugin bundle are uploadedand registered in an AONS management application as follows. The userlogs on to an AONS Management Console (AMC) 604 that the user uses tomanage one or more AONS nodes 606 in the user's network. The userselects the Admin Tab, selects the Transform button, and selects theUpload Transform Package menu item. The user selects the transformbundle file 608 file and clicks UPLOAD. In response, the user interfacedisplays all extensions provided in the package. The user selectsRegister to register the extensions in AMC 604. The same steps arefollowed to load the transform parser plugin bundle 610 for registeringany transform parser extensions.

Registration causes AMC 604 to create and store a transform policy 612that references the transform bundle 608 and contains an instantiatedclass based on the XSLT transform specified in the transform bundle 608.Registration also causes AMC 604 to create and store an XML parserplugin 614 that references the parser plugin bundle 610 and contains aninstantiated class for the parser plugin class defined in the bundle.

To deploy the bundles in an AONS node 606, the following steps areutilized. Working with AMC 604, the user selects a Policy Tab,Application Policy, and Global Level menu item. The user selects thebundle that has the packages registered in steps above. The user selectsDeploy to deploy the bundle.

In an embodiment, transformation information metadata is provided aspart of a transformation bundle. The metadata defines all transformationextensions that are present in a corresponding transformation bundle,which can be either an XSLT transform bundle or a content parser pluginbundle. One or more extensions can be present in a particular bundle. Inan XSLT transform bundle, each extension specifies a name that is usedto identify the extension and serves as a filename, a display name, andversion information. If the bundle is a parser plugin bundle, similarfields specify the class name that implements the XMLReader interface,the display name of the extension, and version information. Table 5presents an example Transformation Bladelet Info File. Table 6 presentsan example XML schema defining the transformation information.

TABLE 5 TRANSFORMATION BLADELET INFO FILE  <?xml version=“1.0”encoding=“UTF-8”?> <!-- XML file generated by XMLSPY v2004 rel. 4 U(http://www.xmlspy.com)--> <bladelet-infoxmlns:xsi=“http://www.w3.org/2001/XMLSchema-instance”xsi:noNamespaceSchemaLocation=“”  name=“transform” displayNameKey=“transform.bladelet.name”  versionId=“1” categoryKey=“transformation.category.name” bundle=“TransformBladelet.properties” bladeletClass=“com.cisco.aons.bladelet.v1.TransformationBladelet”> <icon-ref> <palette-icon href=“sign16Icon.gif”/> <document-iconhref=“sign32Icon.gif”/>  </icon-ref> <exceptions>  <exceptionid=“Transform-Failures” key=“exception.transformfailures.label”desc=“Transform failures” descKey=“exception.transformfailures.desc”  /></exceptions>  <bladelet-design> <bladelet-parameters><configuration-group name=“Transformation” key=“cg.transformation” ><parameter-group name=“ContentToTransform” key=“cg.transformation.xslt.pg.contenttotransform”> <parametername=“Input” type=“ContentListIterator” allowVarBinding=“true”allowUserInput=“false”key=“cg.transformation.xslt.pg.contenttotransform.p.input” /> <parametername=“OverwriteContent” type=“boolean”key=“cg.transformation.xslt.pg.contenttotransform.p.overwritecontent”optional=“true” /> </parameter-group> <parameter-groupname=“ParsingBundle”  key=“cg.transformation.xslt.pg.parsingbundle”><!-- Assuming that the default parser plugin is in the policy set; ifunspecified use the default builtin --> <parametername=“ParserPluginProfile” type=“policy”domain=“com.cisco.aons.transformation.TransformationParserPolicy”key=“cg.transformation.xslt.pg.parsingbundle.p.parserplugin”allowVarBinding=“false” allowUserInput=“false” optional=“true”/></parameter-group> <parameter-group name=“TransformingBundle” key=“cg.transformation.xslt.pg.transformingbundle”> <parametername=“StylesheetProfile” type=“policy”domain=“com.cisco.aons.transformation.TransformationPolicy”key=“cg.transformation.xslt.pg.transformingbundle.p.stylesheetprofile”allowVarBinding=“false” allowUserInput=“false” /> </parameter-group></configuration-group> </bladelet-parameters>  </bladelet-design> <bladelet-deployment> <system-params/>  </bladelet-deployment> <bladelet-runtime> <export-params> <!-- These are parameters that thebladelet puts in the context --> <parameter name=“TransformedContents”key=“transformed.contents” type=“ContentListIterator”/> </export-params> </bladelet-runtime>  <output-paths number=“static”> <output-pathlabel=“success” key=“success.label”/> <output-path label=“fail”key=“fail.label”/>  </output-paths> </bladelet-info>

TABLE 6 TRANSFORMATION BLADELET INFO FILE <?xml version = “1.0” encoding= “UTF-8”?> <!--Generated by Turbo XML 2.4.1.100. Conforms to w3chttp://www.w3.org/2001/XMLSchema--> <xsd:schema xmlns:xsd =“http://www.w3.org/2001/XMLSchema”  elementFormDefault = “qualified”><xsd:element name = “TransformExtensionInfo”> <xsd:complexType><xsd:sequence> <xsd:choice> <xsd:element ref = “TransformInfo”/><xsd:element ref = “ParserPluginInfo”/> </xsd:choice> <xsd:element ref =“AONSVersion”/> </xsd:sequence> </xsd:complexType> </xsd:element><xsd:element name = “TransformInfo”> <xsd:complexType> <xsd:sequence><xsd:element ref = “XSLTTransformName” maxOccurs = “unbounded”/></xsd:sequence> </xsd:complexType> </xsd:element> <xsd:element name =“ParserPluginInfo”> <xsd:complexType> <xsd:sequence> <xsd:element ref =“ParserClassName” maxOccurs = “unbounded”/> </xsd:sequence></xsd:complexType> </xsd:element> <xsd:element name = “AONSVersion”><xsd:complexType> <xsd:attribute name = “version” use = “required”><xsd:simpleType> <xsd:restriction base = “xsd:string”> <xsd:minLengthvalue = “1”/> </xsd:restriction> </xsd:simpleType> </xsd:attribute></xsd:complexType> </xsd:element> <xsd:element name =“XSLTTransformName”> <xsd:complexType> <xsd:attribute name = “name” use= “required”> <xsd:simpleType> <xsd:restriction base = “xsd:string”><xsd:minLength value = “1”/> </xsd:restriction> </xsd:simpleType></xsd:attribute> <xsd:attribute name = “display-name” use = “required”><xsd:simpleType> <xsd:restriction base = “xsd:string”> <xsd:minLengthvalue = “1”/> </xsd:restriction> </xsd:simpleType> </xsd:attribute><xsd:attribute name = “version” use = “required”> <xsd:simpleType><xsd:restriction base = “xsd:string”> <xsd:minLength value = “1”/></xsd:restriction> </xsd:simpleType> </xsd:attribute> </xsd:complexType></xsd:element> <xsd:element name = “ParserClassName”> <xsd:complexType><xsd:attribute name = “class-name” use = “required”> <xsd:simpleType><xsd:restriction base = “xsd:string”> <xsd:minLength value = “1”/></xsd:restriction> </xsd:simpleType> </xsd:attribute> <xsd:attributename = “display-name” use = “required”> <xsd:simpleType><xsd:restriction base = “xsd:string”> <xsd:minLength value = “1”/></xsd:restriction> </xsd:simpleType> </xsd:attribute> <xsd:attributename = “version” use = “required”> <xsd:simpleType> <xsd:restrictionbase = “xsd:string”> <xsd:minLength value = “1”/> </xsd:restriction></xsd:simpleType> </xsd:attribute> </xsd:complexType> </xsd:element></xsd:schema>

TABLE 7 TRANSFORMATION INFO SAMPLE FILE FOR PARSER PLUGIN EXTENSION<?xml version = “1.0” encoding = “UTF-8”?> <TransformExtensionInfoxmlns:xsi = “http://www.w3.org/2001/XMLSchema-instance”xsi:noNamespaceSchemaLocation = “transform-info.xsd”> <ParserPluginInfo><ParserClassName class-name = “sample.csvplugin.CSVReader” display-name= “CSV Parser” version = “1”/> </ParserPluginInfo> <AONSVersion version= “1”/> </TransformExtensionInfo>

TABLE 8 TRANSFORMATION INFO SAMPLE FILE FOR XSLT TRANSFORM EXTENSION<?xml version = “1.0” encoding = “UTF-8”?> <TransformExtensionInfoxmlns:xsi = “http://www.w3.org/2001/XMLSchema-instance”xsi:noNamespaceSchemaLocation =“file:///D:/temp/transformationBundle/TransformExtensionInfo.xsd”><TransformInfo> <XSLTTransformName name = “identity.xslt” display-name =“Identity Transform” version = “1”/> </TransformInfo> <AONSVersionversion = “1”/> </TransformExtensionInfo>

TABLE 9 SAMPLE TEST TRANSFORMATION FLOW <flow description=“This is aTransformation Flow” interactionStyle=“Request-Response” logging=“none”name=“TransformationFlow” sla=“0”> <flow-vars> <flow-vartype=“SearchResultListIterator” name=“ME-Result”/> <flow-vartype=“Content” name=“ME-Content”/> <flow-var type=“ContentListIterator”name=“Input”/> <flow-var type=“ContentListIterator”name=“TransformationResult”/> <flow-var type=“Message”name=“REQUEST_MESSAGE”/> <flow-var type=“Message”name=“RESPONSE_MESSAGE”/> </flow-vars> <flow-steps> <request-actionid=“100” > <first-bladelet id=“1000”/> <bladelet name=“ForwardRequest:1”id=“1000” description=“IO bladelet”> <param-values name=“PARAM-ABC”><value>“This is a test”</value> </param-values> <next-steps><response-link id=“111”/> <!-- <on-exception id=“3”/>--> </next-steps></bladelet> </request-action> <response-action id=“111”> <first-bladeletid=“5000”/> <bladelet name=“TranformationBladelet:1” description=“Bladelet Description”  id=“5000”>  <param-valuesname=“Input” type=“ContentListIterator”><value>$RESPONSE_MESSAGE.content( ).iterator( )</value> <!--<value>$ME-Result.elementAt(0).elementAt(“Label”)</value> --> </param-values>  <param-values name=“UpdateMessage” type=“Message”><value>$RESPONSE_MESSAGE</value> <!--<value>$ME-Result.elementAt(0).elementAt(“Label”)</value> --> </param-values>  <param-values name=“StylesheetProfile” type=“string”> <value>IdentityTransform</value>  </param-values>  <param-valuesname=“ParserPluginProfile” type=“string”> <value>CiscoXSLTTransformation</value>  </param-values> <exported-value name=“TransformationResult” type=“ContentListIterator”bindId=“TransformationResult”/>  <next-steps> <next-step label=“Success”id=“7000”/> <next-step label=“Fail” id=“7000”/>  </next-steps></bladelet> <bladelet  name=“ForwardRequest:1” id=“7000” description=“IObladelet”> <param-values name=“PARAM-ABC”> <value>“This is atest”</value> </param-values> <next-steps> <!--<response-linkid=“2222”/>--> <!--<on-exception id=“3”/>--> </next-steps> </bladelet></response-action> </flow-steps> <compenstation-steps> <first-bladeletid=“1000”/> <bladelet name=“bladelet_5:1” id=“1000”description=“compenstaion step bladelet”> <param-valuesname=“PARAM-ABC”> <value>“This is a compensation steps.”</value></param-values> </bladelet> </compenstation-steps> </flow>

TABLE 10 SAMPLE TRANSFORMATION PARSER POLICY <?xml version=“1.0”encoding=“UTF-8”?> <AttributeDomaindomainName=“TransformationParserPolicy”>  <AttributeDefinitionattributeName=“AONSTransformerFactory”/>  <AttributeDefinitionattributeName=“ParserClassName”/>  <AttributeDefinitionattributeName=“VendorName”/>  <AttributeDefinitionattributeName=“BundleName”/>  <AttributeDefinitionattributeName=“PluginJarFileName”/>  <PropertySetkey=“CiscoXSLTTransformation”> <Attribute name=“AONSTransformerFactory”><!-- This is the default, and need not be specified. This is somethingwe will open up to allow  Java Plugins to handle third partytransformers --> <Valuevalue=“com.cisco.aons.com.cisco.aons.service.transform.XSLTTransformerFactory”/></Attribute> <Attribute name=“ParserClassName”> <!-- sample CSV Parser.This is optional too. -->  <!-- <Valuevalue=“com.cisco.aons.service.transform.CSVReader”/> -->  <Valuevalue=“sample.csvplugin.CSVReader”/> </Attribute> <Attributename=“VendorName”>  <Value value=“acmeInc”/> </Attribute> <Attributename=“BundleName”>  <Value value=“testbundle”/> </Attribute> <Attributename=“PluginJarFileName”>  <Value value=“sample.jar”/> </Attribute> </PropertySet> </AttributeDomain>

TABLE 11 SAMPLE TRANSFORM POLICY <?xml version=“1.0” encoding=“UTF-8”?><AttributeDomain domainName=“Transformation”>  <AttributeDefinitionattributeName=“UseCompiledTransform”/>  <AttributeDefinitionattributeName=“translet-name”/>  <AttributeDefinitionattributeName=“destination-directory”/>  <AttributeDefinitionattributeName=“package-name”/>  <AttributeDefinitionattributeName=“jar-name”/>  <AttributeDefinitionattributeName=“generate-translet”/>  <AttributeDefinitionattributeName=“auto-translet”/>  <AttributeDefinitionattributeName=“ParserClassName”/>  <AttributeDefinitionattributeName=“StylesheetName”/>  <AttributeDefinitionattributeName=“TargetContentType”/>  <AttributeDefinitionattributeName=“TransformerFactory”/>  <AttributeDefinitionattributeName=“VendorName”/>  <AttributeDefinitionattributeName=“BundleName”/>  <PropertySet key=“IdentityTransform”><Attribute name=“StylesheetName”> <Value value=“Identity.xsl”/></Attribute> <Attribute name=“TargetContentType”> <Valuevalue=“text/xml”/> </Attribute> <Attribute name=“TransformerFactory”><Value value=“org.apache.xalan.processor.TransformerFactoryImpl”/></Attribute> <Attribute name=“VendorName”>  <Value value=“acmeInc”/></Attribute> <Attribute name=“BundleName”>  <Value value=“testbundle”/></Attribute>  </PropertySet> </AttributeDomain>

4.0 Implementation Mechanisms—Hardware Overview

FIG. 8 is a block diagram that illustrates a computer system 800 uponwhich an embodiment of the invention may be implemented. The preferredembodiment is implemented using one or more computer programs running ona network element such as a router device. Thus, in this embodiment, thecomputer system 800 is a router.

Computer system 800 includes a bus 802 or other communication mechanismfor communicating information, and a processor 804 coupled with bus 802for processing information. Computer system 800 also includes a mainmemory 806, such as a random access memory (RAM), flash memory, or otherdynamic storage device, coupled to bus 802 for storing information andinstructions to be executed by processor 804. Main memory 806 also maybe used for storing temporary variables or other intermediateinformation during execution of instructions to be executed by processor804. Computer system 800 further includes a read only memory (ROM) 808or other static storage device coupled to bus 802 for storing staticinformation and instructions for processor 804. A storage device 810,such as a magnetic disk, flash memory or optical disk, is provided andcoupled to bus 802 for storing information and instructions.

A communication interface 818 may be coupled to bus 802 forcommunicating information and command selections to processor 804.Interface 818 is a conventional serial interface such as an RS-232 orRS-422 interface. An external terminal 812 or other computer systemconnects to the computer system 800 and provides commands to it usingthe interface 814. Firmware or software running in the computer system800 provides a terminal interface or character-based command interfaceso that external commands can be given to the computer system.

A switching system 816 is coupled to bus 802 and has an input interface814 and an output interface 819 to one or more external networkelements. The external network elements may include a local network 822coupled to one or more hosts 824, or a global network such as Internet828 having one or more servers 830. The switching system 816 switchesinformation traffic arriving on input interface 814 to output interface819 according to pre-determined protocols and conventions that are wellknown. For example, switching system 816, in cooperation with processor804, can determine a destination of a packet of data arriving on inputinterface 814 and send it to the correct destination using outputinterface 819. The destinations may include host 824, server 830, otherend stations, or other routing and switching devices in local network822 or Internet 828.

The invention is related to the use of computer system 800 forapplication message payload transformation in a network infrastructureelement. According to one embodiment of the invention, applicationmessage payload transformation in a network infrastructure element isprovided by computer system 800 in response to processor 804 executingone or more sequences of one or more instructions contained in mainmemory 806. Such instructions may be read into main memory 806 fromanother computer-readable medium, such as storage device 810. Executionof the sequences of instructions contained in main memory 806 causesprocessor 804 to perform the process steps described herein. One or moreprocessors in a multi-processing arrangement may also be employed toexecute the sequences of instructions contained in main memory 806. Inalternative embodiments, hard-wired circuitry may be used in place of orin combination with software instructions to implement the invention.Thus, embodiments of the invention are not limited to any specificcombination of hardware circuitry and software.

The term “computer-readable medium” as used herein refers to any mediumthat participates in providing instructions to processor 804 forexecution. Such a medium may take many forms, including but not limitedto, non-volatile media, volatile media, and transmission media.Non-volatile media includes, for example, optical or magnetic disks,such as storage device 810. Volatile media includes dynamic memory, suchas main memory 806. Transmission media includes coaxial cables, copperwire and fiber optics, including the wires that comprise bus 802.Transmission media can also take the form of acoustic or light waves,such as those generated during radio wave and infrared datacommunications.

Common forms of computer-readable media include, for example, a floppydisk, a flexible disk, hard disk, magnetic tape, or any other magneticmedium, a CD-ROM, any other optical medium, punch cards, paper tape, anyother physical medium with patterns of holes, a RAM, a PROM, and EPROM,a FLASH-EPROM, any other memory chip or cartridge, a carrier wave asdescribed hereinafter, or any other medium from which a computer canread.

Various forms of computer readable media may be involved in carrying oneor more sequences of one or more instructions to processor 804 forexecution. For example, the instructions may initially be carried on amagnetic disk of a remote computer. The remote computer can load theinstructions into its dynamic memory and send the instructions over atelephone line using a modem. A modem local to computer system 800 canreceive the data on the telephone line and use an infrared transmitterto convert the data to an infrared signal. An infrared detector coupledto bus 802 can receive the data carried in the infrared signal and placethe data on bus 802. Bus 802 carries the data to main memory 806, fromwhich processor 804 retrieves and executes the instructions. Theinstructions received by main memory 806 may optionally be stored onstorage device 810 either before or after execution by processor 804.

Communication interface 818 also provides a two-way data communicationcoupling to a network link 820 that is connected to a local network 822.For example, communication interface 818 may be an integrated servicesdigital network (ISDN) card or a modem to provide a data communicationconnection to a corresponding type of telephone line. As anotherexample, communication interface 818 may be a local area network (LAN)card to provide a data communication connection to a compatible LAN.Wireless links may also be implemented. In any such implementation,communication interface 818 sends and receives electrical,electromagnetic or optical signals that carry digital data streamsrepresenting various types of information.

Network link 820 typically provides data communication through one ormore networks to other data devices. For example, network link 820 mayprovide a connection through local network 822 to a host computer 824 orto data equipment operated by an Internet Service Provider (ISP) 826.ISP 826 in turn provides data communication services through the worldwide packet data communication network now commonly referred to as the“Internet” 828. Local network 822 and Internet 828 both use electrical,electromagnetic or optical signals that carry digital data streams. Thesignals through the various networks and the signals on network link 820and through communication interface 818, which carry the digital data toand from computer system 800, are exemplary forms of carrier wavestransporting the information.

Computer system 800 can send messages and receive data, includingprogram code, through the network(s), network link 820 and communicationinterface 818. In the Internet example, a server 830 might transmit arequested code for an application program through Internet 828, ISP 826,local network 822 and communication interface 818. In accordance withthe invention, one such downloaded application provides for applicationmessage payload transformation in a network infrastructure element asdescribed herein.

The received code may be executed by processor 804 as it is received,and/or stored in storage device 810, or other non-volatile storage forlater execution. In this manner, computer system 800 may obtainapplication code in the form of a carrier wave.

5.0 Extensions and Alternatives

In the foregoing specification, the invention has been described withreference to specific embodiments thereof. It will, however, be evidentthat various modifications and changes may be made thereto withoutdeparting from the broader spirit and scope of the invention. Thespecification and drawings are, accordingly, to be regarded in anillustrative rather than a restrictive sense.

The preceding description has disclosed an approach for performingapplication message payload transformation in a network device. Theapplication message payload transformation is performed based onpolicies that are defined declaratively in terms of applicationendpoints and application message content. The approach herein providesan improved application message payload transformation approach becausea network device is more efficient in performing such transformations,which occur outside the application and the host of the application.

The approach herein has numerous benefits over prior approaches. Forexample, the approach reduces the number of processing locations atwhich a message is transformed. Application endpoints are not requiredto perform message payload transformation. As a result, applicationresources can focus on core application functions, rather thantransforming the messages that the application needs to consume based onall other sending applications that are producing such messages.

Further, separating the management of message transformation policiesfrom the actual message transformation enables a user or system todefine such policies declaratively in a single place, and apply them onall the network devices where the transformation is done.

The approach herein is useful for any network gear vendor that needsmechanisms to provide message transformation capability in a networkingdevice to enable easier application integration.

What is claimed is:
 1. A data processing apparatus, comprising: aplurality of network interfaces that are configured to be coupled to adata network for receiving one or more packets therefrom and sending oneor more packets thereto; one or more processors; a switching systemcoupled to the one or more processors and packet forwarding logic,wherein the switching system and packet forwarding logic are configuredto receive packets on a first network interface, determine a secondnetwork interface on which to send the packets, and to send the packetson the second network interface; application message transformationlogic comprising one or more stored sequences of instructions which,when executed by the one or more processors, cause: receiving one ormore packets representing an input application message from a senderapplication to a receiver application; extracting an application messagepayload from the input application message; identifying one or morefirst content elements in the application message payload, wherein theone or more first content elements comprise a first field and a secondfield; wherein the first field is before the second field in the one ormore first content elements; transforming the one or more first contentelements into one or more second content elements of an outputapplication message at least in part by reordering at least the firstfield and the second field to an order that is expected by the receiverapplication, wherein the first field is after the second field in theone or more second content elements, and forwarding the outputapplication message to a destination that is identified in the inputapplication message.
 2. The apparatus of claim 1, wherein the inputapplication message is logically associated with OSI network model Layer5 or above.
 3. The apparatus of claim 1, wherein the application messagetransformation logic comprises sequences of instructions which, whenexecuted, cause transforming the one or more first content elements intothe one or more second content elements further comprises performing atransformation based on one or more of required media types of thereceiver application; security credential mapping; content aggregation;content splitting; service interface virtualization; performingcontent-based lookup, extraction, routing and distribution; contentvalidation; data validation; or code page translation.
 4. The apparatusof claim 1, wherein the apparatus comprises any of a packet data routeror a packet data switch configured to couple to a packet-switchednetwork.
 5. The apparatus of claim 1, wherein the application messagetransformation logic comprises one or more extensible stylesheetlanguage transforms, one or more parser plugin transforms, and one ormore custom transforms that are logically coupled and perform successivetransformation operations on the application message payload.
 6. Theapparatus of claim 1, wherein the application message transformationlogic comprises sequences of instructions which, when executed, causetransforming the one or more first content elements into the one or moresecond content elements comprises changing a data value from the one ormore first content elements.
 7. The apparatus of claim 1, wherein theapplication message transformation logic comprises sequences ofinstructions which, when executed, cause applying an extensiblestylesheet language transformation file to the input application messageto generate the output application message.
 8. The apparatus of claim 1,wherein a first data value corresponds to the first field and a seconddata value corresponds to the second field, wherein the first data valueis before the second data value in the one or more first contentelements, and the application message transformation logic comprisessequences of instructions which, when executed, cause reordering thefirst data value and the second data value, and wherein the first datavalue is after the second data value in the one or more second contentelements.
 9. A machine-implemented method comprising: receiving one ormore packets representing an input application message from a senderapplication to a receiver application; wherein the one or more packetsare received in a network infrastructure data processing elementcomprising a plurality of network interfaces that are configured to becoupled to a data network for receiving one or more packets therefromand sending one or more packets thereto, one or more processors, aswitching system coupled to the one or more processors and packetforwarding logic, wherein the switching system and packet forwardinglogic are configured to receive packets on a first network interface,determine a second network interface on which to send the packets, andto send the packets on the second network interface, and applicationmessage transformation logic; extracting an application message payloadfrom the input application message; identifying one or more firstcontent elements in the application message payload, wherein the one ormore first content elements comprise a first field and a second field,wherein the first field is before the second field in the one or morefirst content elements; transforming the one or more first contentelements into one or more second content elements of an outputapplication message at least in part by reordering at least the firstfield and the second field to an order that is expected by the receiverapplication, wherein the first field is after the second field in theone or more second content elements, and forwarding the outputapplication message to a destination that is identified in the inputapplication message; wherein the method is performed by one or moreprocessors.
 10. The method of claim 9, wherein the input applicationmessage is logically associated with OSI network model Layer 5 or above.11. The method of claim 9, wherein transforming the one or more firstcontent elements into the one or more second content elements furthercomprises performing a transformation based on one or more of requiredmedia types of the receiver application; security credential mapping;content aggregation; content splitting; service interfacevirtualization; performing content-based lookup, extraction, routing anddistribution; content validation; data validation; or code pagetranslation.
 12. The method of claim 9, wherein transforming the one ormore first content items into the one or more second content itemscomprises applying an extensible stylesheet language transformation fileto the input application message to generate the output applicationmessage.
 13. The method of claim 9, wherein transforming the one or morefirst content elements into the one or more second content elementsfurther comprises removing a field and a corresponding data value fromthe one or more first content elements.
 14. The method of claim 9,wherein a first data value corresponds to the first field and a seconddata value corresponds to the second field, wherein the first data valueis before the second data value in the one or more first contentelements, and wherein reordering at least the first field and the secondfield comprises reordering the first data value and the second datavalue, and wherein the first data value is after the second data valuein the one or more second content elements.
 15. A non-transitorycomputer-readable storage medium storing one or more sequences ofinstructions, which instructions, when executed by one or moreprocessors, cause the one or more processors to perform: receiving oneor more packets representing an input application message logicallyassociated with OSI network model Layer 5 or above, wherein the inputapplication message is from a sender application to a receiverapplication; wherein the one or more packets are received in a networkinfrastructure data processing element comprising a plurality of networkinterfaces that are configured to be coupled to a data network forreceiving one or more packets therefrom and sending one or more packetsthereto, one or more processors, a switching system coupled to the oneor more processors and packet forwarding logic, wherein the switchingsystem and packet forwarding logic are configured to receive packets ona first network interface, determine a second network interface on whichto send the packets, and to send the packets on the second networkinterface, and application message transformation logic; extracting anapplication message payload from the input application message;identifying one or more first content elements in the applicationmessage payload; wherein the one or more first content elements comprisea first field and a second field; wherein the first field is before thesecond field in the one or more first content elements; transforming theone or more first content elements into one or more second contentelements of an output application message at least in part by reorderingat least the first field and the second field to an order that isexpected by the receiver application, wherein the first field is afterthe second field in the one or more second content elements, andforwarding the output application message to a destination that isidentified in the input application message.
 16. The non-transitorycomputer-readable storage medium of claim 15, wherein the inputapplication message is logically associated with OSI network model Layer5 or above.
 17. The non-transitory computer-readable storage medium ofclaim 15, further comprising sequences of instructions which whenexecuted cause performing a transformation based on one or more ofrequired media types of the receiver application; security credentialmapping; content aggregation; content splitting; service interfacevirtualization; performing content-based lookup, extraction, routing anddistribution; content validation; data validation; or code pagetranslation.
 18. The non-transitory computer-readable storage medium ofclaim 15, further comprising sequences of instructions which whenexecuted cause applying an extensible stylesheet language transformationfile to the input application message to generate the output applicationmessage.
 19. The non-transitory computer-readable storage medium ofclaim 15, further comprising sequences of instructions which whenexecuted cause removing a field and a corresponding data value from theone or more first content elements.
 20. The non-transitorycomputer-readable storage medium of claim 15, wherein a first data valuecorresponds to the first field and a second data value corresponds tothe second field, wherein the first data value is before the second datavalue in the one or more first content elements, and wherein furthercomprising sequences of instructions which when executed causereordering the first data value and the second data value, and whereinthe first data value is after the second data value in the one or moresecond content elements.